1. Field of the Invention:
The present invention relates to automatic cooking apparatus, and more specifically to a system for dispensing liquids in such apparatus.
2. Background of the Invention:
U.S. Pat. No. 4,649,810 entitled "Automatic Cooking Apparatus" discloses a cooking apparatus, in which ingredients are automatically dispensed into a cooking vessel and heated, stirred, covered, and uncovered according to a prescribed recipe. In one embodiment of that invention, the ingredients are preloaded into a compartmentalized carousel which rotates on command under the control of a microprocessor to bring the appropriate compartment into position for dispensing its ingredients into the vessel. Since recipes often call for the addition of liquids, including liquids with suspension of small particles and granular materials, to be truly automatic the cooking apparatus must include a mechanism for automatically dispensing such ingredients.
Liquid ingredients present a problem not shared by chopped onions, cubed beef, or other solid ingredients--liquids tend to leak through even the smallest opening. Compartments or chambers intended to hold liquid ingredients must be sealed against such leakage and in the past have generally required complicated mechanisms to break the seal at the right time for dispensing the ingredients into the cooking vessel. The liquid-dispensing apparatus disclosed in U.S. Pat. No. 4,649,810, for example, employs an elastomeric stopper, which is urged by a spring-biasing mechanism into a sealing position in a dispensing orifice so as to maintain a good seal, and which is opened by a cam mechanism involving two rotatable cams. In this arrangement a portion of the mechanism is disposed inside the chamber and is immersed in the liquid to be dispensed. This arrangement diminishes the volume available for the liquid and makes cleaning more difficult.
The design of an automatic liquid dispensing system, suitable for use in cooking apparatus intended for the domestic kitchen, involves a tradeoff of such factors as reliability--will it always work without leaking: durability--will it withstand the normal abuse encountered in the domestic kitchen and continue to work; compactness--does it make the cooking apparatus unappealingly bulky or unwieldy manufacturing cost--does it make the cooking apparatus too expensive for typical households: and especially cleanliness--can the mechanism be cleaned easily and thoroughly.